Identification, quantification and analysis of observable anthropogenic debris along swiss river and lakes (IQASL)¶
IQASL is a project sponosored by the Swiss Federal Office for the environment to quantify shoreline trash along swiss lakes and rivers in the Rhone, Aare, Ticino and Linth/Limmat catchment areas. This is accomplished by conducting multiple small scale and discrete litter surveys throughout the river bassin. The majority of samples are taken from lakes.
What is a litter survey?
A litter survey is the identification and count of all objects found within a delimited area, in this study all surveys were bordered on one side by water. Each object is placed into one of 260 categories¹. The location, date, survey dimensions and the total number of objects in each category is noted.
Purpose of the surveys
The survey results help ALL stakeholders identify the items that make up the mass of trash found in the natural environment on the shores of Swiss lakes and rivers. The surveys answer the following questions:
- What items are found?
- How much is found ? (total weights and item counts)
- How often are these items found?
- Where do you find the most?
These are the most frequently asked questions and should be considered when determining any mitigation or reduction strategies.
The project is based on the following assumptions:
- The more trash there is on the ground the more a person is likely to find
- The survey results represent the minimum amount of trash at that site²
- For each survey: finding one item does not effect the chance of finding another³
Purpose of this report
Summarize the results for the survey area and define the magnitude of those results with respect to other survey areas.
The survey results are presented as follows:
- Total object count, total weight and weight of plastics
- The most abundant objects from the survey area and all the other survey areas sorted by total object count
- Pieces of trash per meter (pcs/m): the ratio of number of objects found to the length of the shoreline
- Objects that were found in at least 50% of the surveys
Contents of this report
Scope: description of river basin
- survey locations
- lakes and rivers
- municipalities and effected population
Survey dimensions, locations, aggregated totals
- weights and measures: cumulative
- weights and measures: cumulative by water feature
- survey totals: pcs/m by date
- material type: % of total
Trash removed: most abundant objects
- the most common objects from the survey area
- the most common objects from all the survey areas
- pcs/m of most common objects for all water features in the survey area
- objects that are found in more than 50% of surveys
- objects that are the most abundant
- objects found in less than 50% of the surveys
- utility classification: % total of all objects found
- effective data: report of missing records
- survey location coordinates
- population profile and results by municipality
- itemized list of objects removed
More information
For more information about the project visit project home.
If you would like more information specific information about this survey area please contact:
- Swiss federal office for the environment - Municipal waste section
- analyst@hammerdirt.ch
¹ The EU guide on monitoring marine litter
² There is most likely more trash at the survey site, but certainly not less than what was recorded.
³ Independent observations : stats stackexchange
Scope¶
The Aare source is the Aare Glaciers in the Bernese Alps of south-central Switzerland. The Aare is the longest river entirely within Switzerland with a length of 295 km and drainage area of 17,779 km2. Following the Aare Gorge, the river expands into the glacial Lake Brienz. The Aare is canalized at Interlaken before entering Lake Thun and exiting through the city of Thun.⁵ The river then flows northwest surrounding the old city center of Bern on three sides. Continuing west to Lake Wohlen Reservoir it turns north to Aarberg and is diverted west into Lake Biel by the Hagneck Canal, one of a series of major water corrections made in the 19th and 20th centuries connecting Neuchatel, Biel and Morat lakes through canalization. From the upper end of Lake Biel, at Nidau, the river exits through the Nidau-Büren Canal/Aare Canal.⁶
The Limmat and Reuss rivers⁷, two major tributaries converge into the Aare at the Limmatspitz between the cities of Brugg and Untersiggenthal in Canton Aargau.⁸ The Aare river ends in the north-western region of Koblenz, Switzerland where it joins the Rhine river which eventually terminates in the North Sea.
⁵ The Editors of Encyclopaedia Britannica. (1998, July 20). Aare River. Retrieved from Britannica.com: https://www.britannica.com/place/Aare-River
⁶ Standard Encyclopedia of Worlds Rivers and Lakes. (1965) R.K. Gresswell
⁷ The Limmat and Reuss are part of different survey areas
⁸ Pro Natura . (n.d.). Limmatspitz. Retrieved from Pro Natura : https://www.pronatura-ag.ch/de/Gebenstorf-limmatspitz
Survey locations, municipalities¶
Cumulative totals by water feature¶
Survey totals pieces per meter, material type % of total¶
The most abundant objects: results by water feature¶
Some objects are found throughout the survey area and some of those objects are found in all survey areas. Knowing which objects are most abundant and what those values are helps idenitify sources or zones of accumulation.
Some objects are found often and in elevated quantities, others are found often and in small quantities and some times objects are found less often but in large quantities. Knowing the diffference can help find the sources.
Utility: percent of total objects collected¶
Utility: The utility type is based on the utilisation of the object prior to it being discarded. Objects are placed into to one of the 260 categories. Those categories are grouped according to utilisation.
For example, a piece of plastic would be placed into the category 'Fragmented plastics', depending on its size. However, a piece of plastic that was once a bucket and we know this because we are familiar with either the brand or the product, is placed in a code for buckets⁸.
- wastewater: items released from water treatment plants includes items likely toilet flushed
- micro plastics (< 5mm): fragmented plastic items and pre-production plastic resins
- infrastructure: items related to construction and maintenance of all infratructure items
- food and drink: primarily single use plastic items related to consuming food and drinks outdoors
- agriculture: primarily industrial sheeting includes
- tobacco: primarily cigarette ends includes all smoking related material
- recreation: includes fishing, hunting, boating and beach related objects, excludes food, drink and tobacco items
- packaging non food and drink: packaging or wrapping material not identified as food, drink nor tobacco related
- plastic fragments: foam and plastic fragments of indeterminate origin and use
- personal items: accessories, hygiene and clothing related
⁸ See the annex for the complete list of objects identified, includes category and group classification
More information¶
Contact hammerdirt.ch for any questions about the content of this report. If you would like a report for your municipality contact the Swiss federal office for the environment: Municipal waste section.
Population profile
The samples come from a variety of locations. Certain locations were sampled at monthly intervals others through out the year. Almost 90% of the surveys come from lakes within the survey area, here we consider the number of samples and the pcs/m per survey rating for all lake samples in the survey area.
¶
The median pieces per meter per survey of the most abundant objects by municipality
Survey locations: